import java.util.*;
class Example2_5 {
  public static void main (String args[]){
    int start = 0, end, middle;
    int a[] = {12, 45, 67, 89, 123, -45, 67};
    int N = a.length;
    for (int i = 0; i<N; i++){
    for (int j = i+1; j<N;j++){
      if(a[j] < a[i]){
        int t = a[j];
        a[j] = a[i];
        a[i] = t;
      }
    }
  }
  Scanner scanner =new Scanner(System.in);
  System.out.println("输入整数，程序判断该整数是否在数组中：");
  int number = scanner.nextInt();
  int count = 0;
  end = N;
  middle =(start+end)/2;
  while (number!=a[middle]){
    if(number>a[middle])
      start = middle;
      else if (number<a[middle])
      end = middle;
      middle = (start + end )/2;
      count++;
      if(count > N/2)
      break;
  }
  if (count > N/2)
    System.out.printf("%d不在数组中.\n",number);
  else
    System.out.printf("%d在数组中.\n",number);
  }
}

